csplit.cpp

研读AxCrypt对加解密的处理方法

/*! \file
    \brief Implementation of AxPipe::CSplit base class for Y-split

    @(#) $Id: CSplit.cpp,v 1.3 2004/02/02 12:10:47 svante Exp $

    AxPipe - Binary Stream Framework

    Copyright (C) 2003 Svante Seleborg/Axon Data, All rights reserved.

    This program is free software; you can redistribute it and/or modify it under the terms
    of the GNU General Public License as published by the Free Software Foundation;
    either version 2 of the License, or (at your option) any later version.

    This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
    without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
    See the GNU General Public License for more details.

    You should have received a copy of the GNU General Public License along with this program;
    if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
    Boston, MA 02111-1307 USA

    The author may be reached at mailto:[e-mail] and http://axpipe.sourceforge.net

    Why is this framework released as GPL and not LGPL? See http://www.gnu.org/philosophy/why-not-lgpl.html

----
\verbatim
    CSplit.cpp                      Implementation of CSplit base class for Y-split

    E-mail                          YYYY-MM-DD              Reason
    [e-mail]              2003-12-01              Initial
\endverbatim
*/
#include "stdafx.h"

#include "AxAssert.h"
#define AXLIB_ASSERT_FILE "CSplit.cpp"

namespace AxPipe {
    /// This is called by the base class destructor.
    /// Destruct the chain, waiting for parts of it to finish and skipping
    /// parts that should not be auto-destructed. It will call delete for those
    /// sections that are marked for auto-destruction. We need to override the
    /// the base class definition, since we're not using m_pSink to point to
    /// the rest of the chain.
    void
    CSplit::DestructSink() {
        // Here we do a safety first, so we can be called even if it's not
        // properly constructed.
        if (m_pLeft) {
            m_pLeft->WorkExitWait();
            delete m_pLeft;
        }
        if (m_pRight) {
            m_pRight->WorkExitWait();
            delete m_pRight;
        }
        m_pLeft = m_pRight = NULL;
    }
    /// \brief Send the same segment down both left and right legs of the split
    /// \param pSeg Pointer to a segment to send
    void
    CSplit::PumpSplit(CSeg *pSeg) {
        pSeg->AddRef();
        m_pLeft->OutPump(pSeg);
        m_pRight->OutPump(pSeg);
    }

    /// \brief Construct and initialize the member variables.
    CSplit::CSplit() {
        m_pLeft = NULL;
        m_pRight = NULL;
    };

    /// Normally append a sink, but not valid for CSplit
    /// \param pSink Pointer to an instance of a CSink derived object.
    /// \param fAutoDeleteSink true if the object should be delete'd when the member upstream is delete'd.
    void
    CSplit::AppendSink(CSink *pSink, bool fAutoDeleteSink) {
        SetError(ERROR_CODE_GENERIC, _T("Use Init() for CSplit"));
    }

    /// Synchronize all work downstream, ensuring
    /// that there is no work in progress.
    void
    CSplit::Sync() {
        WaitForIdle();
        m_pLeft->Sync();                    // Wait for the rest of the pipe too.
        m_pRight->Sync();                   // Wait for the rest of the pipe too.
    }

    /// \brief Initialize split with left and right pointers to pipes.
    ///
    /// The provided pointers to CPipe are always auto delete'd. Errors occurring
    /// in either of the two splits are aggregated backwards to the original CSource.
    /// \param pLeft Pointer to left pipe, does not start with a  CPipe, but ends with a CSink
    /// \param pRight Pointer to right pipe, does not start with a  CPipe, but ends with a CSink
    /// \return A pointer to 'this' CSplit.
    CSplit *
    CSplit::Init(CPipe *pLeft, CPipe *pRight) {
        (m_pLeft = pLeft)->CError::Init(this);
        (m_pRight = pRight)->CError::Init(this);
        return this;
    }
    /// \brief Send the same segment downstream to both parts of the split.
    /// \see CPipe::Out()
    void
    CSplit::Out(CSeg *pSeg) {
        PumpSplit(pSeg);
    }

    /// \brief Send the same special segment downstream to both parts of the split.
    /// \return false. Never indicate propagation, as this object in many ways is a sink.
    /// \see CPipe::OutSpecial()
    bool
    CSplit::OutSpecial(CSeg *pSeg) {
        PumpSplit(pSeg);
		return false;
    }
    
    /// \brief Send a flush signal downstream to both parts of the split.
    ///
    /// \return false. Never indicate propagation, as this object in many ways is a sink.
    /// \see CPipe::OutFlush()
    bool
    CSplit::OutFlush() {
        PumpSplit((new CSeg)->SetType(eSegTypeFlush));
        return false;
    }
    
    /// \brief Send a close signal downstream to both parts of the split.
    ///
    /// Never indicate propagation, as this object in many ways is a sink.
    /// \see CPipe::OutClose()
    bool
    CSplit::OutClose() {
        PumpSplit((new CSeg)->SetType(eSegTypeClose));
        return false;
    }
    
    /// \brief Send an open signal downstream to both parts of the split.
    ///
    /// Never indicate propagation, as this object in many ways is a sink.
    /// \see CPipe::OutOpen()
    bool
    CSplit::OutOpen() {
        PumpSplit((new CSeg)->SetType(eSegTypeOpen));
        return false;
    }
};